Burden and determinants of anemia among lactating women in Ethiopia: evidence from demographic health survey

Globally one-third of global population are victims of anemia, significantly impacting maternal and infant health and linked to poor cognition, productivity, and mortality risks. We used randomly selected 4040 lactating mothers’ record from nationally representative survey. Descriptive statistics were weighted, and the standard hemoglobin cutoff point (below 12 g/dl) was used. Bivariable and multivariable multilevel binary logistic regression model considering the individual and community-level factors associated with anemia was employed. Crude and adjusted odds ratios with a 95% confidence interval were reported. In Ethiopia, 32.3% (95% CI 30.9–33.7%) of lactating women were anemic, with 23.4% having mild, 7.3% moderate, and 1.2% severe anemia. Pastoral regions (Afar, Somalia, and Oromia region) had higher burden of anemia than the others. The advanced age of the mother above 45 years (AOR = 1.43 (1.11–1.82), unemployment (AOR = 1.19; 95% CI 1.08–1.32), household wealth index (AOR = 0.56; 95% CI 0.50–0.63), extended family size (AOR = 1.20; 95% CI 1.04–1.46), and not using family planning (AOR = 1.70; 95% CI 1.49–1.93) were significant factors associated with anemia. Anemia is a moderate public health problem and associated with location and other factors to be addressed via effective interventions.


Data sources
The current paper is based on secondary analysis of the 2016 EDHS survey, spanning all regional states and the two federal administrative cities of Ethiopia.Ethiopia is a country that is located in the eastern parts of Africa, within Sub-Saharan Africa.An estimated total population of more than 110 million people resides in the country.The survey was conducted in 2016 from January to June.The data were collected from a nationally representative sample of households in a way that allows national and regional levels estimates of indicators.The results of this analysis targeted all lactating mothers (currently breast-feeding mothers during the data collection period) based on a representative sample of lactating mothers from a randomly selected household.The data nature and coding were reviewed thoroughly to extract important variables and observations.Considering the breast-feeding status during the interview (V404) and the pregnancy status, we extracted 4252 data of lactating women interviewed for the survey.The missing values for the outcome variable was checked, and all cases of the lactating women were included in the analysis (n = 4040) Data was captured from a representative enumeration area and 11 administrative regions of the country.

Variables of the study
The anemia status of the lactating mother was a dependent variable while many socio-demographic, obstetric, diet-related, and other related variables were considered as potential independent variables in the study.Some of the variables included were region, residence, age of the mother, household wealth index, maternal occupation, mother's educational status, husband's education, family planning use, marital status, nutritional status of the mother, substance use (alcohol, cigarette and khat chewing).
It is known that different cut-off points are used to diagnose anemia based on the WHO standard anemia (based on hemoglobin measurement) classification adjusted for different life stages (pregnancy, childhood, women of reproductive age and adult males), smoking status, and altitude.Hence, for lactating women who are within women of reproductive age group, hgb concentration value below 12.0 g/dl were classified as anemic.Moreover those with 10-11.9g/dl as mild, 7-9.9 g/dl as moderately anemic and below 7 g/dl as severely anemic 1 (Table 1).

Data analysis
The data was acquired in SPSS format and the analysis was done in SPSS version 20.The data was presented in frequency, percentage, tables, and graphs.The body mass index (kg m −2 ) was calculated and classified as underweight (less than 18.5 kg m −2 ), normal (18.5-24.9kg m −2 ), and overweight (above 25 kg m −2 ).The household asset variables were analyzed using a principal component analysis after checking that all assumptions were carried out.Then, the factor score is used to categorize individuals into wealth quintiles (poorest, poorer, middle, rich, and richest).For the present analysis, the wealth index was presented into three groups (poor, middle, and rich) better presentation.
A bivariable and multivariable multilevel binary logistic regression analysis was carried out to identify determinants of anemia.Variables found statistically significant at p-value below 0.25 during bivariable analysis were analyzed in the multivariable logistic regression model.Crude and an adjusted odds ratio with a 95% confidence level was calculated.Statistical significance was declared at a p-value below 0.05.Multicollinearity and effect modifications were evaluated accordingly using variance inflation factor (above 10) and interaction effects.

Ethical approval and consent to participate
The dataset was obtained from the DHS site with a full legal request.The dataset will not be shared with the third party.These are anonymous surveys, which do not allow any potential identification of any single household or individual in the data file.The survey protocol, including biomarker sample collection, was reviewed and approved by the Federal Democratic Republic of Ethiopia's Ministry of Science and Technology and the Institutional Review Board of ICF International.Written informed consent was obtained from all subjects and/or their legal guardian for those aged less than 18 years.The accessed data were used for the purpose of registered research paper.Confidentiality of the data was kept and no effort made to identify any household or individual respondent interviewed in the survey.The data were not passed on to other researchers without the written consent of DHS.The data were fully accessed at www. dhspr ogram.com.All methods were carried out in accordance with Declaration of Helsinki.These data were captured using interviewer administered questionnaire and through face-to-face interview Household wealth index Collected using the extended household asset questionnaire and the wealth index was constructed using the principal component analysis Anthropometric measurements (Body mass index) The weight and height of mothers was captured using standardized anthropometric measurement and used to assess nutritional status based on body mass index, where below 18.5 (undernutrition), 18.5-24.9(normal), 25-29.9(overweight) and above ≥ 30 (obese) Vol:.( 1234567890)

Socio-demographic and economic characteristics
Out of the total 4252 records, 4040 (95% retrieval rate) records of lactating women were included in the analysis after excluding 67 (1.6%) records due to anemia status not available although sample were collected and 145 (3.4%) were excluded due to maternal refusal or to give blood sample at the start.A total of 800 (18.8%) were from urban areas, and the majority (47.1%) were aged 26-35 years of age.Around 2431 (63.1%) had no education at all (illiterate), and 1683 (43.6%) were Muslims.Almost one-third, or 1439 (33.8%) of lactating women were living in the poorest wealth quintile, while only 559 (13.1%) were from the richest quintile.The majority, 3994 (94%) and 2331 (57.7%), were married and unemployed, respectively.About 648 (15.2%), (13.4%), and (12.3%) were from the Oromia, southern, and Amhara regions of Ethiopia (Fig. 1).

Burden and distribution of anemia
In Ethiopia, 1306 (32.3%; 95% CI 30.9-337%) of lactating women were anemic; 23.4%, 7.3%, and 1.2% had mild, moderate, and severe anemia, respectively.A wide interregional variation in the prevalence of anemia was observed among regions where pastoral regions (Afar, Somalia, and Parts of Oromia regions) had the highest prevalence of anemia (Fig. 2).Anemia among lactating women was more prevalent among women residing in rural area and in the age group of 26-35 years as compared to counterparts.Women in the lowest socioeconomic class were the most prone to anemia.In addition, the burden of anemia was higher among married and uneducated women (Table 2).
Anemia was highly prevalent in Somalia's regional states (67.2%), followed by Afar (48.6%) and Dire Dawa (43.2%).Specifically severe anemia was higher in Somalia (6.5%) and Afar (2.5%).However, mild anemia was more prevalent across all regional and city administrations.Furthermore, in certain regions like Addis Ababa and Gambelia, no cases of severe anemia were identified (Table 3).

Factors associated with anemia among lactating mothers
In bivariable analysis, the age of the mother, residence, maternal education, household wealth index, household family size, marital status, and alcohol use was associated with anemia in the crude model.Women aged 26 to  www.nature.com/scientificreports/35 years (COR = 1.25; 95% CI 1.03-1.52),living in rural areas (COR = 1.80; 95% CI 1.65-1.95),and being married (COR = 1.25; 95% CI 1.2-13) had a 25%, 80%, and 25% higher risk of anemia as compared to counterparts, respectively.Women in a higher the higher wealth quintile (COR = 0.42; 95% CI 0.38-0.48)and had lower risks of anemia compared to lower wealth quintile in the crude model.Women in the higher family size had a 40% increased risk of being anemic (COR = 1.40; 95% CI 1.25-1.60).Concerning substance use, alcohol consumption is associated with reduced risk of anemia (COR = 0.51; 95% CI 0.46-0.55)while association with khat chewing and cigarette smoking did not show statistical significance.In addition, the risk of anemia was found to be higher among undernourished women (COR = 1.29; 95% CI 1.16-1.34)and lower among obese women (COR = 0.66; 95% CI 0.52-0.84)compared to well-nourished mothers in the unadjusted model.Those lactating mothers who never used any family planning methods (COR = 2.36; 95% CI 2.06-2.70)and unemployed mothers (AOR = 1.54; 95% CI 1.34-1.76)had 2.36 and 1.54 times higher odds of anemia compared to counterparts (Table 4).
After adjusting for potential confounders, a stepwise multivariable logistic regression model was fitted (Hosmer-Lemeshow's p-value = 0.89).The age of the mother, household wealth index, educational status of the women, occupation of the women, household family size, and family planning use were significantly associated with anemia.Women with higher wealth quintile (AOR = 0.56; 95% CI 0.50-0.63)had a lower odd of anemia  www.nature.com/scientificreports/than women with lower socioeconomic status.Better husband education showed to proportionally decrease the odds of anemia among lactating women as compared to those without formal education (P-value < 0.0001) where those who attended primary (AOR = 0.79; 95% CI 0.70-0.90),secondary (AOR = 0.82; 95% CI 0.72-1.10)and higher education secondary (AOR = 0.75; 95% CI 0.56-1.03)had 21%, 18% and 25% reduced odds of anemia, respectively.Unemployed mothers (AOR = 1.19; 95% CI 1.08-1.32)and women with extended family size (household size) above seven (AOR = 1.20; 95% CI 1.04-1.46)had about 20% higher risks of anemia compared to employed and mothers with smaller household size.Those who did not use family planning (AOR = 1.7; 95% CI 1.49-1.93)was associated with increased risks of anemia among lactating mother (Table 5).

Discussions
The findings of this study showed that 32.3% of lactating women had anemia indicating anemia a moderate public health problem in Ethiopia.Also, the advanced age of the mother above 45 years unemployment, household wealth index, extended family, and not using family planning were significant factors associated with anemia.The current estimate is slightly higher than the 2005 (29.9%) and 2011 national DHS (18.5%) 21.However, a relatively consistent result was found as compared to the study done in Madrid (29%) 27 .In contrast, studies conducted in India (60-82%) 24 , Myanmar (60.3%) 28 , and Vietnam (39.0%) 29 , showed a higher burden of anemia among lactating women.Sub-national evidence has also showed that anemia affects 43% 13 and 28.7% of lactating Table 4. Unadjusted logistic regression model for factors associated with anemia among lactating women in Ethiopia.p-value below 0.05 (*), 0.005 (**), and 0.0005 (***).BMI was categorized as low or undernourished (BMI below 18.5 kg/m 2 ), normal (18.5-24.9kg/m 2 ), overweight (25-29.9kg/m 2 ) and obese (> 30 kg/m 2 ).www.nature.com/scientificreports/women in the Northwest and South West Ethiopia, which is above the estimate in Amhara (12.3%) and the Oromia region (15.3%) 30 .Furthermore, a great inter-regional variation in anemia prevalence was observed 12 , where anemia is more prevalent in the pastoral and agropastoral regions, which could be linked to many dietary and non-dietary factors.For instance, this might be related to a higher reliance on cow or camel milk, which is a rich source of calcium, affecting iron absorption negatively.In addition, we noted a persistently increasing burden of anemia from 2005 to 2016 in Ethiopia 21 , which indicates that the existing interventions might not be effective and due attention is not given for lactating women.On the contrary, more recent estimates depicted that 13% of women in reproductive age had anemia with a consistently higher occurrence among women from Somalia (40%) and Dire Dawa 30 .This may be associated with differences in socio-economic status and dietary behaviors 2,11,13,22 .In addition, the current study is based on a country wide large-scale survey, which is inclusive of women from multiple socioeconomic and dietary habits contexts 12,29 .It is partly explained by the increased blood loss during delivery, coupled with poor dietary habits and prevailing maternal malnutrition further predisposing women to higher risks of anemia 9,20,22,23 .Hence, anemia during pregnancy which persists while lactation could potentially increase the risks maternal morbidity, mortality, maternal cognition, and poor childhood development, which warrants context-specific interventions addressing anemia like tailored iron and folic acid supplementation schedules Overall, this study indicated that anemia among lactating women is an important public health problem, that needs to be addressed through targeted interventions 7,15 .Larger family size and not using family planning was found to be associated with higher odds of anemia among lactating women.This is consistent with evidence from India that showed family planning use was preventive for anemia (AOR = 0.68; 95% CI 0.57-0.80) 31.Pooled analysis of the 2005 and 2011 EDHS 21 also showed that family size and non-use of family planning were significantly associated with increased occurrence of anemia.Other studies conducted in Ethiopia has also showed a similar association 13,16,19,32,33 .These are mainly explained with the critical link between family size and the issue of maternal depletion syndrome associated with short interpregnancy intervals.Moreover, it could be linked with food insecurity and nutrient loss due to subsequent pregnancy increasing the burden of the mother.Efforts to maintain an optimal birth interval could reduce the risk of maternal depletion and may allow better food and nutrition security for better nutritional status of mothers 34 .This might be partly explained by the inverse relationship between maternal age and hemoglobin (AOR = 0.8; p = 0.004), which is supported by study done in Southwest Ethiopia (β = − 0.03; 95% CI; 0.04 0.03) 13 .
In contrast, increased maternal age is associated with repeated pregnancy, expanded family size, and increased maternal depletion.However, it could be linked to being primigravida, which is associated with increased blood loss due to pregnancy complications in the earlier periods 2,23 .While evidence from Southwest Ethiopia indicated that maternal age had no any significant association with anemia 35 .While our study indicated that advanced maternal age was associated with a higher burden of anemia.On the other hand, better maternal education reduces the risk of anemia by 75% (AOR = 0.75; 95% CI 0.56-1.03)as compared to illiterates.Those primigravida within the teenager group might have an increased double burden of pregnancy and adolescents.Meeting the iron and vitamin requirements of women during adolescence could contribute to a reduced burden of anemia 11 .Studies have also showed that adolescents were more at risk for anemia (22%) 36,37 , which could be associated with the double nutrient burden.This will allow decision maker to target anemia prevention and control strategies focusing on high-risk groups, with enhanced family planning utilization for achieving optimal fertility level and improve nutritional status 5,14 .This study showed that women from better economic classes reduced the risk of anemia by half.A study from Myanmar and previous national estimates indicated that better income is associated with a lower risk of anemia which could allow for better food security, educational status, and knowledge of healthy behaviors 3,20,31 .It may also be linked to having better ANC and post-natal visits and adherence to iron and folic acid supplementation 36,37 .In this research majority of lactating women's having anemia had not history of ANC follow up accounts 509 (49%).This emphasizes the need for enhance nutritional counseling and full package delivery during ANC visit could improve the nutrition intake and health behaviors in post-natal period 14,[38][39][40] .
This evidence clearly shows that anemia is a public health problem among lactating women.Little interventions for addressing anemia among lactating women are there in Ethiopia where routine iron and folic acid supplementations are not in place.Hence, little attention is being given to it despite its adverse consequences, which are mainly related to problems with iron intake 30,41,42 .Intermittent iron supplementation could be an alternative short-term strategy in areas of high anemia burden to supplement existing interventions.
However, the findings of this analysis could be frustrated by many factors.For instance, the old nature of the data could not allow to depict the existing burden of anemia rather it would allow for comparative trends.Hence, the current country insecurity, food security issues and food inflation might have worsened the issue further.

Conclusions
Anemia among lactating women is a moderate public health problem that needs a targeted and effective intervention to address it.Higher age, larger family size, maternal illiteracy, poor socioeconomic class, and not having family planning use history were found to be associated with anemia.There may be a need for countryspecific and cost-effective interventions via enhanced family planning, improving food and nutrition security, and intermittent iron supplementation could be a potential strategy to address the current burden of anemia.Thus, interventional studies and pilots could help to further understand the potential feasibility, compliance and effectiveness of such interventions in addressing anemia among lactating women.

Figure 1 .
Figure 1.Sample cluster (enumeration areas) distribution for sample household for the 2016 EDHS in Ethiopia.

Figure 2 .
Figure 2. Prevalence and levels of anemia among lactating women in Ethiopia, based on the 2016 national DHS data for Ethiopia.

Table 1 .
Summary of the study variables and measurements.

Table 2 .
Prevalence and degree of anemia by different sociodemographic and socioeconomic characteristics of lactating women in Ethiopia.

Table 3 .
Prevalence and degree of anemia estimates disaggregated by region among lactating women in Ethiopia.